This invention relates to a method and an apparatus for opening a plurality of textile fiber bales, particularly compressed cotton bales. The fiber is removed from the top of the bales by an opening device which comprises a spiked roll, toothed discs or the like and which projects through a grate and extends into the upper face of the fiber bales.
As a result of the operation of conventional bale opening apparatuses of the above-outlined type, the opening rolls leave, on the face of the bales, parallel grooves separated by parallel ridges; these latter, in turn, are formed in the contact (pressure) areas between the grate and the bale surface. It has been found that it is difficult to remove the fiber material from the ridge portions because the latter cannot be directly attacked by the spikes or teeth of the opening device but can be only entrained laterally by the directly removed fiber material. Further, the fiber material constituting the ridge portions are even further compressed by the pressing effect of the grate bars. Thus, it has been found that such ridges can be removed only with difficulty and only very gradually in sevral consecutive passes. This adversely affects the efficiency of the apparatus to a significant degree.
To remedy the above-discussed disadvantage, it has been known to periodically change the relative lateral position between bale and grate. Thus, in the apparatus disclosed in German Pat. No. 1,118,067, the fiber bales are periodically shifted with respect to the grate. Such shifting arrangement is disadvantageous in that the fiber bales have a substantial weight and are in general not easy to handle. Further, the opening rolls, while movable vertically, are, however, not displaceable with respect to the grate bars.